The rapid development of the motion analyses systems and computer-controlled devices has introduced possibility of new ways of interacting with computers. One preferred method is to use different body parts as a commanding device, i.e. using movements to enter commands into the operating system of the computer or control peripheral devices.
However, the known methods and systems are rather complex and usually analyse the entire body or a large area.
In WO 99/34276, a system and method for constructing three-dimensional images using camera-based gesture inputs of a system user is described. The system comprises a computer-readable memory, a video camera for generating video signals indicative of the gestures of the system user and an interaction area surrounding the system user, and a video image display. The video image display is positioned in front of the system users. The system further comprises a microprocessor for processing the video signals, in accordance with a program stored in the computer-readable memory, to determine the three-dimensional positions of the body and principle body parts of the system user. The microprocessor constructs three-dimensional images of the system user and interaction area on the video image display based upon the three-dimensional positions of the body and principle body parts of the system user. The video image display shows three-dimensional graphical objects superimposed to appear as if they occupy the interaction area, and movement by the system user causes apparent movement of the superimposed, three-dimensional objects displayed on the video image display.
According to U.S. Pat. No. 6,002,808, a system is provided for rapidly recognizing hand gestures for the control of computer graphics, in which image moment calculations are utilized to determine an overall equivalent rectangle corresponding to hand position, orientation and size, with size in one embodiment correlating to the width of the hand. In a further embodiment, a hole generated through the utilization of the touching of the forefinger with the thumb provides a special trigger gesture recognized through the corresponding hole in the binary representation of the hand. In a further embodiment, image moments of images of other objects are detected for controlling or directing onscreen images.
A method and an apparatus are described in U.S. Pat. No. 5,576,727 for use with a computer for providing commands to a computer through tracked manual gestures and for providing feedback to the user through forces applied to the interface. A user manipulatable object is coupled to a mechanical linkage, which is, in turn, supportable on a fixed surface. The mechanical linkage or the user manipulatable object is tracked by sensors for sensing the location and/or orientation of the object. A multi-processor system architecture is disclosed wherein a host computer system is interfaced with a dedicated microprocessor which is responsive to the output of the sensors and provides the host computer with information derived from the sensors. The host computer has an application program, which responds to the information provided via the microprocessor and which can provide force-feedback commands back to the microprocessor. The force feedback is felt by a user via the user manipulatable object.